Air-Tite Coin Capsule "A" Black Ring Coin Holder for 13mm Coins Air-Tite holders are made from an acrylic plastic with a non-yellowing agent to ensure the crystal clear display your coins for any length of time. The rings are made of an inert cross-linked polyethylene which secures the coin in the holder and blocks air contamination. All materials used in the production of the coin capsule coin holders and rings are totally inert and PVC free. The outside diameter of the "A" holder is 1.218" (30.93mm).